The present invention relates to a magnetic disk drive mechanism, and more particularly to a magnetic disk drive mechanism which includes a magnetic disk drive motor whose stator base is part of a chassis of the magnetic disk drive mechanism.
Magnetic disk drive mechanisms are widely used in magnetic information storage devices for computers and information processing systems.
The magnetic disk drive mechanisms include magnetic disk drive motors for rotating magnetic disks. A magnetic disk drive motor for a small-size magnetic disk drive mechanism which rotates a 3.5-inch magnetic disk is small in size and usually housed within a hub which holds the central hole in the magnetic disk. The magnetic disk drive motor of this type is known as the in-hub magnetic disk drive motor.
One conventional magnetic disk drive mechanism includes a box-shaped chassis which defines a hermetically sealed chamber therein. The hermetically sealed chamber houses therein a magnetic disk and an in-hub magnetic disk drive motor for rotating the magnetic disk. The in-hub magnetic disk motor includes a stator base fastened to the chassis and a printed-circuit baseboard mounted on the stator base, the printed-circuit baseboard including printed coil patterns for frequency and pulse generators for detecting the rotational speed and phase of the motor. The stator base and the printed-circuit baseboard are of a double-layer construction, which makes the magnetic disk drive mechanism relatively thick. The printed coil patterns are soldered to lead wires within the hermetically sealed chamber, and special care should be taken to prevent dust particles from being scattered from the soldered terminals into the hermetically sealed chamber. It is also difficult to reliably seal the lead wires which extend from the hermetically sealed chamber through a hole defined in the stator base of the motor because the hole cannot easily be filled up with a resin adhesive.